This is gotta be the craziest post I've ever read. Don't ever intentionally cause set in a bow. That is insulting and disrespectful to it's maker and the bow itself. Although I don't know why the bowyer sent you a string that cannot be strung with the bow. Your measuring from nock to nock, right? How heavy draw weight is the bow? Yes, dacron is not too good for a warbow. Although I have used one on a 100# warbow before, it was only about 3 1/2" or so maybe from nock to nock at most, it was a 20 strand b50. It did stretch unbelievably far, and you could feel it stretch during draw, but I have no idea what is going on if your string is 10" shorter than the nock to nock length. That is ridiculous. I have no idea what is going on. Oh, and I use ff plus, it works just dandy for me.